Method of electric-arc welding, heating, and metal-working, and apparatus therefor.



C. L. COFFIN. METHOD OF ELECTRIC ARC WELDING, HEATING, AND METALWORKING, Ann APPARATUS THERc'FOR APPLICATION HLED FEB- 1917' PatentedOct. 30, 19171;

1 r R ii VA w. 1 QM my 2 a a. (N ,w a A V Om FATN if CHARLES I1. COFFIN,OF PARKS, GEORGIA,

ASSIGNOR T0 ELECTRIC METAL WORKING 00., OF DETROIT, MICHIGAN, ACORPORATION OF MICHIGAN.

METHOD OF ELECTRIC-ARC \VELIDING, HEATING, AND METAL-WORKING, AND

APPARATUS THEREFOR.

1,244 %05. Specification of Letters Patent. Patented 0 ,34), 1917.

Continuation of application Serial No. 89,128, filed April 5, 1916. Thisapplication filed. February '7, 1917.

Serial No. 147,188.

To all whom it may concern:

Be it known that I, CHARLES L. CorrIN, a citizen of the United States,residing at Parks, in the county of White and State of Georgia, haveinvented new and useful Improvements in Methods of Electric-Arc Welding,Heating, and Metal-Working, and Apparatus Therefor, of which thefollowing is a specification.

The present invention relates to an improved method of welding andheating metals by means of the electric arc, and apparatus therefor. Theprimary object of the invention is to utilize the direct heat of theelectric arc, while in contact with the material to be heated, bycausing the material to be made one electrode of the arc and anextraneous conductor the other electrode of the arc, and to moreuniformly and broadly distribute the heatin action of the arc, the arcis caused to describe a path upon the material in the manner hereinafterdescribed. For this purpose, a tool or electrode holder is providedwhich is so constructed and arranged that an extraneous electrode may bemade to describe a path of'motion over the material,thus causing the'arcto travel in a path over the materialand thereby distribute its heatingeffect. In its simplest form of application, the electrode and,conjointly, the arc, may be made to describe a simple path, such as acircle; but to more thoroughly distribute the heating action of the arcthe electrode is caused to describe two paths of motion, that is to say,it is caused to revolve about one axis, and also to revolve or moveindependently in a path of its own while describing the first-mentionedpath. I have found that if the electrode is made to revolve while movingover a prearranged path, there is less fluctuation or disturbance of thearc, and this fact may be used to advantage in more broadly distributingthe heating action of the arc, as in the arrangement hereinafterdescribed.

In the present practice of welding by an electric arc sprung between thematerial and an extraneous conductor, the operator, to avoid overheatingor burning the material, or even puncturing it with the arc, is compelled to move the electrode about rapidly by hand, generally causingthe electrodeto describe a circle of greater or less diameter and withvarying speed as may be required.

This procedure is laborious, exacting, and requires great muscularexertion and skill on the part of the operator, more especially whenengaged in an operation of considerable magnitude.

My present invention obviates this and provides a method simple andeasily applied by purely mechanical means in a tool carried in the hand,simplifying the welding operation, preventing overheating, and makingresults more certain.

The present application is a continuation of my co-pending application,Serial No. 89,128, filed April 5, 1916.

In the accompanying drawing:

Figure 1 shows in side elevation, partly in section, a hand tool forelectric arc welding,

heating, and metal worln'ng embodying the 7 present invention, theelectric circuits therefor being shown diagrammatically.

Fig. 2 is a top plan view of the tool as shown in Fig. 1.

Fig. 3 represents a section on the line 33 of Fig. 1.

Figs. t and 5 are detail sectional views showing modifications of theinvention.

Similar parts are designated by the same reference characters in theseveral views.

Preferably, and as shown, the tool comprises an insulated handle 1provided with a shield or guard 2- to protect the hand of the operatorwhile grasping the handle. A sleeve 3 is secured to one end of thehandle and it has a forwardly extended bracket 4 and a pair of supports5 which extend upwardly therefrom. A bracket 6 is secured to the sleeve3, and it provides a bearing 7 for the upper end of the shaft of anarmature 8, this armature forming part of an electric motor the polepieces 9 of which are secured to the supports 5, these pole pieceshaving field coils 10 thereon, and the motor has a stud 11 which isseated in the sleeve 3. By the construction just described, the pole orfield pieces of the motor are supported in fixed relation to the handleand its connected parts while the armature 8 of the motor is revoluble.12 designates the brush holder of the motor. The lower end 13 of thearmature shaft extends downwardly through a sleeve 14: which is acontinuation of the bracket 1, and the'armature shaft is provided with acollar 15 which sustains downward or end thrust on the armature shaft.An arm 16 is secured by a set-screw 1701' other suitable means to thelower end of the armature shaft, and, in the construc tion shown inFigs. 1, 3 and 4, this arm is bored vertically to form a. bearing 18. Anelectrode holder 19 is revolubly fitted in the bearing 18 of the arm 16,it having a friction collar 20 thereon at the upper side of the arm 16and a separately formed collar 21 secured at the underside of the arm 16whereby the electrode holder is revoluble in the bearing 18 and endwisedisplacement of the electrode holder relatively to the arm 16 isprevented. During the operation of the tool, rotation of the armatureshaft causes rotation of the arm 16 about the axis of the armatureshaft. Such motion of the arm 16 will cause the electrode holder totravel in a. circular path the axis of which is coincident with the axisof the armature shaft. In the construction shown in Figs. 1, 3 and 4,rotation is imparted to the electrode holder to cause rotation of theelectrode carried thereby. As shown, the electrode holder is drivenfrictionally during rotation of the arm 16, such being accomplished bythe collar 20 on the electrode holder engaging frictionally andtraveling around a circular collar 22 formed on the lower portion of theextension 14 of the bracket 4. In Figs. 1 and 2, the electrode holder isbored eccentrically of its axis of rotation and is fitted with anelectrode X. In Fig. 4, the electrode holder is bored concentrically ofits axis of revolution to receive the electrode X. In some instances,however, where extensive distribution of the heat of the arc isunnecessary, a construction such as: shown in Fig. 5 may be used. Inthis instance, a bracket 23 is fixed to the lower end 13 of the armatureshaft, and an electrode holder 24 is employed which has a slide 25 whichis secured adjustably to the bracket 23 by a clamping screw orequivalent device 26 whereby the distance of the electrode X in theelectrode holder 24 from the center of the armature shaft may be variedand, in consequence, the electrode may be caused to describe circles ofdifi'erent diameters.

As shown in Fig. 1, the work or material IV to be operated on serves asone of the electrodes of the arc, it being connected by the conductor toto one terminal of a generator or other source of electric currentsupply G, and the conductor 3 leads from the other terminal of thegenerator to the controlling arm 1* of a hand-controlled rheostat It,the conductor y leading from the rheostat through the insulated handleof the tool to a screw 27 whereby current is conducted to the sleeve 3and from the latter it passes through the bracket 4, the extension 14 ofthe bracket to the electrode holder 19, and from the latter to theelectrode X, the circuit being completed by the arc sprung between theelectrode and the work or material under treatment. The electric motoris preferably connected in shunt with the arc circuit. As shown, themotor receives current from one terminal of the generator G through aconductor 2 which leads to the field coils 10 of the motor, thencethrough the brushes and armature windings of the motor, and the motorcircuit is completed through a starting and speed-controlling rheostat28 which is secured to the bracket 6 and embodies a switch lever 29adapted to cooperate with the resistance contacts 30, the switch leverhaving an insulated handle 31 which may be manipulated conveniently bythe thumb of the hand grasping the handle 1. The motor circuit iscompleted from the starting and speed-controlling rheostat to the otherterminal of the generator by a conductor 2 leading to the screw 27, thelatter being electrically connected to the conductor y.

In practice, the mode of procedure is as follows: The hand tool and theworkbeing connected to the generator or other suitable source ofelectrical energy as described and with all of the resistance of therheostat It in circuit, the operator manipulates the tool to bring theelectrode X into contact with the material IN. This completes theelectric circuit, the current then flowing from the generator throughthe conductor to to the work IV, thence through the electrode X and theelectrode holder 19 to the extension 14, and from the latter through thebracket 4 and sleeve 3 to the screw 27, the current then flowing throughthe conductor 2 through the rheostat R, and returning through theconductor y to the opposite terminal of the generator. After the circuithas been thus completed, the operator withdraws the electrode graduallyfrom the work, thereby establishing an are between the work and theelectrode. During the withdrawal of the electrode from the work, theresistance of the rheostat R is cut out of the circuit by manipulationof the controlling or switch lever r, this being continued until the archas assumed the desired volume. The motor is then started into operationby manipulation of the handle 31 connected to the switch lever 29 of thestarting and speed-controlling rheostat of the motor, thereby cuttingout of the motor circuit resistance until the motor revolves at thedesired speed. Rotation of the motor armature causes rotation of the arm16 connected thereto and carrying the electrode holder 19, and while theelectrode holder revolves about the axis of the armature shaft, it isalso caused to re volve in its bearing 18 by the frictional engagementof the collars 20 and 22, the collar 20 on the electrode holdertraveling around the stationary collar 22. In the arrangement shown inFigs. 1 and 2, the electrode is mounted in the electrode holdereccentrically of the axis of the bearing 18 and, in consequence, theelectrode will describe a relatively small circular path about the axisof the electrode holder while it coincidently describes a larger circleabout the axis of the armature shaft. It will therefore be understoodthat, in this embodiment of the invention, the electrode describes twopaths of motion over the work or material, causing the heating effect ofthe arc to be distributed evenly and uniformly during the travel of thearc and without requiring effort on the part of the operator, theoperator being at liberty to shift the tool about as different portionsof the work are to be heated, thereby avoiding the tiresome and exactinglabor of causing the electrode to describe paths or circles over thework by manual manipulation, as is the present practice to distributethe heating effect of the are.

In such cases where extensive distribution of the heat of the arc isunnecessary, the electrode may be mounted concentrically with the axisof revolution of the electrode holder, as is the case in Fig. 4. In thisinstance, the electrode revolves on its own axis or on an axiscoincident with the axis of revolution of the electrode holder while theelectrode describes a circular path about the armature axis as a center.In both instances, however, the electrode revolves relatively to theaxis of the electrode holder, and this causes the arc to be muchsteadier and less liable to fluctuation or disturbance. In other cases,it will be suflicient to move the arc in a circular path about thearmature shaft as an axis without imparting an independent rotation ofthe electrode, such an arrangement being shown in Fig. 5.

I claim as my invention 1. The method of arc welding and heating,consisting in subjecting the material to the heating action of anelectric arc, and causing the arc torevolve about an axis and to alsorevolve independently of such axis.

2. The method of arc welding and heating, consisting in subjecting thematerial to the heating action of an electric are maintained between thematerial and an extraneous electrode and coincidently revolving saidelectrode about one axis while revolving about a second axis todistribute the heating effect of said arc.

3. In the art of electric arc welding, heating and metal working,providing an are between the material to be heated and an extraneouselectrode, and distributing the heating effect of the are bycoincidently imparting to the extraneous electrode two paths of motionover the material.

4. In the art of electric arc welding, heating and metal working,maintaining an are between the material to be heated and an extraneouselectrode, and distributing the heating effect of the are bycoincidently giving the are two paths of motion over the material.

5. The method of distributing the heating action of the arc in arcwelding, consisting in providing an are between the material to beheated and an extraneous electrode, and coincidently giving the are twopaths of motion over the material.

6. Themethod of distributing the heating action of the arc and securingsteadier action of the arc flame in arc welding and heating, consistingin providing an are between the material to be heated and an extraneouselectrode, and coincidently revolving the said extraneous electrodeabout one axis while said electrode revolves about a second axis.

7 An arc welding hand tool comprising a support, an electrode movablymounted thereon, means for connecting said electrode to a source ofelectric energy, and means for coincidently imparting to said electrodetwo paths of motion over the material.

8. An arc welding hand tool comprising a support, an electric motorconnected to a source of electric energy and carried on said support, anelectrode connected to a source of electric energy and adapted to berevolved by said motor, and means for varying the speed of revolution ofthe electrode.

9. An arc welding hand tool comprising a support, an electric motor,means for including the motor in an electric circuit, an electrode forthe arc, means for supporting the electrode, means for connecting theelectrode to a source of electric energy, and means for revolving saidelectrode by said motor.

10. An arc welding hand tool comprising a support, an electric motor, acircuit including the motor, and means for varying the speed of themotor, an electrode for the are, means 'for supporting the electrode,means for connecting the electrode to a source of electric energy, andmeans for imparting to the electrode a path of motion over the material.

11. An arc welding hand tool comprising a support, an electric motor, acircuit including the motor, and means for controlling the motor, anelectrode for the are, means for supporting the electrode, meansconnecting the electrode to a source of electric energy, and means forimparting to the electrode two paths of motion over the material.

12. An arc welding hand tool comprising a support, an electric motor, acircuit including the motor, and means for controlling the motor, anelectrode for the are so mounted upon said motor shaft as to revolveconcentrically with the axis of revolution, and means for varying thedistance of the electrode from the axis of revolution.

13. An arc welding hand tool comprising a support, an electric motor, acircuit inclnding the motor, and means for controlling the motor, anelectrode for the arc carried upon the armature shaft of said motor insuch manner as to revolve the arcing end of said electrode in a circleconcentric with the axis of revolution of the armature shaft, and meansfor varying the diameter of such concentric circle of revolution.

M. An arc welding hand tool comprising a support, an electric motor, acircuit in cluding the motor, and means for control ling the motor, anelectrode for the are adapted to revolve concentrically with the axis ofrevolution of the armature shaft of said motor, and means for causingthe electrode to revolve upon an independent axis during its revolutionabout the axis first mentioned.

15. An arc Welding hand tool comprising a support, an electrode for theare, means for supporting the electrode, means connecting the electrodeto a source of electric energy, and means for revolving the electrodewhile imparting to the electrode a path of motion over the material.

16. In an apparatus for arc welding and heating, the combination of asource of electric energy, two electrodes in circuit therewith, one ofthe electrodes comprising the material to be heated, said electrodesadapted to maintain an electric are between them, means for regulatingsaid arc, a support carrying one of the electrodes, and means forrevolving the last-mentioned electrode about an axis while coincidentlyrevolving it about a second axis.

17. In an apparatus for arc welding and heating, the combination of asource of electric energy, two electrodes in circuit therewith, one ofsaid electrodes comprising the material to be heated, said electrodesadapted to maintain an electric are between them, means for regulatingthe are, a support carrying one or the electrodes, means for re volvingsaid latter electrode about an axis while coincidently revolving itabout a second axis, and means for varying the speed of the movingelectrode.

18. In an apparatus for arc welding and heating, the combination of asource of electric energy, tWo electrodes in circuit therewith, one ofsaid electrodes comprising the material to be heated, said electrodesadapted to maintain an electric are between them, means for regulatingthe arc, a support carrying one of the electrodes for manually0-perating it, and means for coincidently imparting to said latterelectrode two paths of motion over the material.

19. In an apparatus for arc welding and heating, the combination of asource of e1ectric energy, two electrodes in circuit there with, one ofsaid electrodes comprising the material to be heated, said electrodesadapted to maintain an electric are between them, means for regulatingthe are, a manually operable support having the other electrode movablymounted thereon, means for imparting to said latter electrode a path ofmotion about one axis and coincidently imparting thereto motion about asecond axis, and means for varying the speed of the moving electrode.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

CHARLES L. COFFIN. Witnesses J. H. SWAN,

J. H. NELLs.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

